Method of recovering earth components from wells



M. H. KoTzEBUE 2,104,327

METHOD OF RECOVERING EARTH COMPONENTS FROM WELLS Jan. 4, 1938.

Filed DGO. 6, 1935 IBIIE lL Patented Jan. 4, 19h38 PONENTS FROM Meinhard H. Kotzebue, Tulsa, Okla. Application December 8, 1935, Serial No. 58,141 o 11 Claims. (Cl. 1665-21) This invention relates to new and useful improvements in methods bf recovering earth components from wells.

.An object of the invention is to provide a v method whereby recovery of hydrocarbons and other base earth components such as carbon dioxide and helium may be effected in a new and improved manner and specially substantially without waste and with a view of eifecting conl@ servation of the natural resources of the earth.

An important object of the invention is to carry out such method by means of a selective normally liquid absorption medium having aiiinity for the particular components which it is desired to recover. f

Another object of the invention is to provide a method for recovering earth components from a well whereby the stream which is flowed from the Well may be conducted through suitable ap- 30 paratus for separatihgbut the absorption medium and taking of! certain desirable components, and if desirable returning to the well with the absorption medium certain other components-which are noty to be retained at the surface. l

'I'he method involves certain `other objects and advantages which will behereinafter more particularly pointed out and for the purpose of illustrating the operation of the method and ap-v paratusfor carrying out the sama-I have shown in the accompanying drawing a diagrammatical illustration of a well and apparatus located on the surface and connected with said well.

In the drawing, the numeral IU designates the casing of a well, and Il the usual casing head. As the invention has a wide use the well may be one producing gas, oil, or other fluids and/or liquids. The casing maybe cemented as indicated in the drawing or it may merely be anchored in the Well and the head provided with hold-down Acables or rods l2 suitably fastened. In the producing sand or strata, it is customary to either perforate the casing or to provide a screen I3 which extends, as a rule, to the cap rock, or other overlying structure. The usual tubing I4 45 extends from the bottom of the well up through the head il and out through a stuillng box I5.

The tubing may be connected to a T `IS from which a pipe l1 extends. A suitable valve I8 for controlling the ilow may be connected in the pipe 50 Il near the T. y'

The pipe Il is connected with the pipe i9 extending to the lower portion of an ordinary vertical absorber or separator. It is to be observed that no new equipment is employed in this .55 method and any device or devices now in use or which may be put into use, and are suitable for the purpose, may be used. It is .customary in the separation of hydrocarbons to provide a gas and liquid separator of any approved type o0 with staggering baille platesV 2l. The fluid nowing from the'weli and entering the lower portion of the absorber is under suillcient pressure to carry it upward therein. The heavier liquids or liquid hydrocarbons will be scrubbed out of the ascending iluid so as to collect in the bottom of the absorber. The gaseous fluids such as ethane and methane and others will ascendv to the top of the absorber andpass out through a pipe 22 in the usual manner. These iiuids may be conducted to a `suitable `device for further treatment or they may be otherwise conserved. Where such gases are of little value they maybe disposed of in a suitable manner.

The Vliquid hydrocarbons are conducted from the bottom of the absorber 20, by way oi' .a pipe 23, to a heat exchanger 24`and treated therein in the usual manner. The liquid hydrocarbons from the heat exchanger are then carried by way oi.' a pipe 25 to a preheater 26 and thence by a pipe 21 to an evaporator 28. As is customary, the de-n sited fractions are distilled from the absorption liquidin this evaporator. These desirable fractions orgaseous hydrocarbons or distiilatesy are carried from the evaporator by a pipe 2'9, which may beconnected with an ordinary gasoline plant or other treating appartus which'is not shown.

The absorption' liquid or fluid being denuded or robbed of the desirable fractionsl or hydrocarbons collects in the bottom of the evaporator and is drawn ytherefrom by a pump .which is connected with the bottom ofthe evaporator by a pipe 3l, the heat exchanger 24, a pipe 32, a cooling` device 33 and a pipe 34. Theabsorption liquid passing through the heat exchanger 24 heats the liquid hydrocarbons which pass to and through the heat exchanger on theirway kto the evaporator, and the heating'of the liquid hydrocarbon extracts heat vfrom the separated absorption liquid, resulting invan initial cooling of the absorption liquid. The absorption liquid is further cooled in the cooler 33 to the desired tem perature for return to the well. The heat exchanger 24 is not necessary to the successful operation of the present invention. but is desirable since it performs a heat exchange between the liquid hydrocarbons going to the evaporator and the denuded absorption liquid leaving the evaporator. This not only saves some of vthe-heat in the denuded absorption material but reduces proportionately the amount of cooling necessary in the cooler 33. It is desirable to cool the liquid after it has .passed through the heat exchanger.

The return absorptiony liquidA discharged from the pump is delivered by a pipe 35. to pipes 36 and 31. The pipe 31 includes a valve 38 which is normally' closed but which may be opened to permit a portion of the return liquid to enter the upper end of vthe absorber `ior the purpose of dampening orl retarding the upward passage `of the gaseous uids and also for the purpose of recluding a control valve 4I.

absorbing any desirable fractions. The main return line 36 extends to a chiller 39 which is connected with the casing head' II by a pipe 40 in- The' pipe 3|, which extends from the bottom of the' evaporator, may have a valved outlet 42 so that any excess or surplus inthe return fluid may be bypassed. This outlet 42 may be connected with a pipe 43 which is connected with a pump 44, which in turn is connected by a pipe 45 with the return pipe 30 in advance of the-chiller. Surplus products may be introduced into the system at this point or the circulating absorption liquid or iluid may be replenished by this connection or any other suitable manner, as by introduction into the evaporator.

Referring to the cycle of operation, it will be apparent. that the absorption medium, which may be any one oi' the commercial absorption liquids known in the art of refining petroleum oils such as gas oil, kerosene, or absorption oil having a. boiling point between 400 and 600 Fahrenheit, or any one of the known absorption liquids having an absorbingl attraction for carbon dioxide or helium, depending on the nature of the material to be withdrawn from the well, may be pumped down the casing I0 and upon reaching the upper portion of the screen I3 or perforations in the casing just below the cap rock, will ow outwardly into the sand or strata as indicated by the curved arrows. Among the known absorbents for helium are carbon disulfide, acetone, kerosene and gas oil; for hydrogen sulfur, dioxide and gelatin are good absorbents to eliminate other gases; for carbon dioxide, triethylamine and monoethylamine are good absorbents for pressure absorption. In passing downwardly through the zone of the sand, the absorbing medium will become enriched with the hydrocarbons or other components produced in such zone. Where the produced components are liquid they will admix with the absorption medium and Where they are gaseous they will be carried out in solution. Owing to the flowing pressure this absorption stream will pass upwardly through the tubing I4. At this point it might be well to state that the method could be reversed and the absorption stream conducted down the tubing and out into the sand, whereby the return stream would pass up the casing; however, I prefer to use the method illustrated.

It will be seen that operating under usual conditions in a well producing no or very little liquid hydrocarbons, and a large amount of gaseous hydrocarbons, it is almost impossible to recover heavy hydrocarbons without producing excessive amounts of the normal gaseous material. Where the bottom-hole pressure is particularly high, as per illustration, in excess of 2000 pounds, a corresponding high pressure would be produced above the surface which is not only dangerous but interferes with a proper recovery. It is customary under such conditions to waste large volumes of valuable gaseselther by discharging into the atmosphere or by burning as a torch. Such waste aside from the safety question is detrimental to conservation of natural resources. Where an absorption liquid is pumped down into the well, it is possible to hold the pressure at the bottom of the well and to seal-oi the gaseous hydrocarbons so that the stream which is delivered by the tubing will have a much lower pressure, as for instance, lessthan 1000 pounds and as such may be safely and economically handled. The fluid, that is, the absorption liquid and such earth components as it has picked up from the well through the mutual action of the absorption liquid and the earth components, which is discharged from the tubing I4 is conducted by way of the pipes I1 and I9 to the absorber 20. The lighter gases escape from thetop of the absorber through the pipe 22 while the heavier hydrocarbons are carried out vthrough the pipe 23 to the heat exchanger 24. The routine from the heat exchanger by way of the pipe 25, pre-heater .26 and pipe 21, to the evaporator 28 is in accordance with the common practice and it is not considered necessary to describe the same, except to say that the absorption medium is recovered in the bottom of the evaporator after the desirable fractions have been removed. 'Ihe recovered absorption medium becomesthe return liquid and passes out through pipe 3|, through the heat exchanger 24 and pipe 32 to the cooler 33. It is desirable to reduce the heat of the return fluid. The circulation is maintained through the pump 30 which receives the absorption or return liquid from the cooler by way of pipe 34 and discharged it through pipe 35 into the return line 36 which is connected with the casing head I I by the pipe 40. This liquid passes through the chiller 39 whereby its temperature is reduced to a degree which is desirable for recirculating in the well.

The natural laws of governing the absorption of various hydrocarbons, admixtures thereof and other materials existing in the ground such as helium, hydrogen, carbondioxide and the like are well known by those familiar with the art of extraction of such materials from the earthl and their refining with which art the present invention is clearly allied, and for this reason the technicalities of absorption have not'been entered into in this description, but it is obvious that the amount of material and the character of the material absorbed will depend to a large extent upon the kind of absorption material, the pressures, temperatures, degree of contact, length of contact time and the proportionate amounts of absorbing material, which are used. Very successful results have been obtained by using a heavy hydrocarbon liquid as the absorption medium for certain components, but various other mediums which are not hydrocarbons may be used. By passing the return liquid through the cooler 33 and the chiller 39 its temperature is reduced so that its absorption emciency is increased.

In some localities certain hydrocarbons or other components from the well, may be picked up by the absorption liquid, and it being impractical to use the same, they may be returned to the well with the return stream. Following the laws of fractionation and absorption, the greater part of such returned products will remain in the producing zone; however those products which have a great amnity for the particular absorption medium used, will replace such returned products, or will permit further absorption of like material thereby preventing wastage. The cycle of operation mayv also be desirable as an aid to counteract the heat of absorption, because heatk is required to effect separation. It would be possible to introduce other gaseous or liquid material to replace the products taken from the subterranean basin in order to maintain pressure, regulate temperature or to dissolve materials in the strata to more eiilciently accomplish the purpose of this method.

It is to be understood that the invention is not to be limited to use in oil and gas wells as it may be equally as well employed where a well is producing other earth components such as helium and carbon dioxide. Those skilled in the art as above referred to will be able to determine the particular character of the absorption medium necessary to recover the desired components. It would also be possible to select and recover certain earth components by employing an absorption medium for which such components had an aillnity and which medium would not absorb the undesirable components. While the devices which have been illustrated are particularly adaptable to a gas and/or oil well, it is obvious that any devices suitable for the particular components being recovered may be used.

What I claim and desire to secure by Letters Patent, is:

l. In the art of wells, the method of recovering selected gaseous or `liquid earth components which consists, in circulating a liquid absorption medium into the well and through the subterranean basin and out of said well, and removing from the subterranean basin by circulation and absorption the heavier normally liquid products having higher boiling points from normally gaseous mixtures and at the same time removing but a small proportion o! components which are not condensable except under very high pressures and low temperatures.

2. In the art of producing gasoline from wells, the method of stripping the gasoline content from the natural gas by circulating a liquid absorbing medium having an afilnity for the gasoline content through the well and its basin, removing a major portion of the gasoline content and a minimum proportion of natural gas, then separating the gasoline content from the saturated liquid absorbing medium,` cooling theY liquid absorbing medium, and re-circulating the liquid absorbing medium through the well and its basin.

3. In the art of wells, the method of recovering selected gaseous or liquid earth components which includes, circulating a selective liquid absorption medium into the well and through the producing strata, removing from the well selected components by said absorption medium, and then treating the stream flowing from the well to -separate desirable components and then returning the liquid absorption medium to the well, whereby a cycle of operation is maintained.

4. In the art of wells, the method of recovering selected gaseous or liquid earth components from wells having an inherent gas pressure, which includes introducing Aa cooled liquid absorption medium into the top of the well and circulating it in and out of the well and through the producing strata. surrounding the bottom of the well, and removing from the producing strata ascertained components having an afnity for the liquid absorption medium and leaving in the natural basin other components.

5. In the art of wells, the method of conservation of earth components which consists, in introducing a cooled selected liquid absorption medium into the well and circulating it therethrough also forcing said liquid absorption medium in suillcient quantity through the well for passing it through the producing strata, selecting from the producing strata by character of the absorption medium used portions of certain liquid and gaseous components and leaving in the strata usable portions of liquid and gaseous components, re-

turning the liquid absorption medium laden with the selected components to the surface, separating the usable components from the laden absorption medium, cooling the absorption medium, and returning the cooled liquid absorption medium to the well.

6. In the art of wells, the method of recovering selected gaseous or liquid earth components which includes ity only for selected components of the petroleum removing only the absorbed selected components and the absorption liquid from the strata and leaving the other components in the natural basin.

8. In the art of wells, the method of conservation of earth components which includes, circulating a liquid absorption medium in and out or the Well and through the producing strata surrounding the well, which liquid absorption medium has an 'afilnity for the gasoline content and certain gaseous contents of the strata, and removing from the strata and well a iluid consisting of a major portion of gasoline and the selected gas, separating the gasoline and gas from the liquid absorption medium, and re-circulating the liquid absorption medium through the well.

9. In the art of wells, the method o! conservation oi' earth components which includes, circulating a liquid absorption medium in and out of the well and through the producing strata, which liquid absorption medium has an ailinity for the gasoline content, and removing from the strata a iiuid consisting of a major portion of gasoline, separating the gasoline from the liquid absorption medium, and re-circulating the liquid absorption medium through the well.

10. In the art of wells, the method of conservation of earth components which includes, circulating a liquid absorption medium in and out of the well and through the producing strata. which liquid absorption medium has an afllnlty for the gasoline content, and removing from the strata a fluid consisting of a major portion of gasoline, separating the gasoline from the liquid absorption medium, cooling the liquid absorption medium and re-circulating the cooled liquid absorption medium through the well.

11. In the art of wells, a method of recovering selected gases or liquid earth components which includes, forcing a liquid absorption medium having an alnity for the components to be recovered, downwardly through the well and out into the producing area in a quantity suiilcient to fill the producing'area adjacent to the well and block off the direct passage of gases to the well, withdrawing the liquid absorption medium and absorbed earth components from the producing strata through liquid absorption medium and the absorbed components, and returning the liquid absorption medium through the well and producing strata.

MEINHARD H. KOTZEBUE.

the well, separating the f 

